The present invention relates to a hermetically sealed scroll compressor, and is particularly preferable for a hermetically sealed scroll compressor for refrigeration/air conditioning and for helium.
As a conventional scroll compressor, there is the scroll compressor for compressing a gas such as air and a refrigerant, which is disclosed in JP-Y2-1-17669.
The scroll compressor of JP-Y2-1-17669 is constituted of a cylindrical casing, a fixed scroll which is provided by being fixed to the casing to close the end surface of the casing and has a spiral wrap vertically provided on a mirror plate, and a orbiting scroll which is located in the casing and provided turnably at a drive shaft, and has a spiral wrap, which forms a plurality of compression chambers while orbiting by overlapping the wrap of the fixed scroll, vertically provided on the mirror plate. Two oil injection ports are provided in the mirror plate of the fixed scroll to be separated in the radius direction, and the space in the radius direction of the respective oil injection ports is set to be equal to or a little larger than the tooth thickness of a wrap portion of the orbiting scroll. Each of the oil injection ports communicates with one oil supply port. Further, the oil injection port at the center portion side is placed to communicate with the orbiting outer compression chamber in the state in which the wrap of the orbiting scroll is in contact with the outer side of the wrap of the fixed scroll.
Further, as the conventional hermetically sealed scroll compressor, there is cited the hermetically sealed scroll compressor for helium which is disclosed in JP-A-2004-232481.
In the hermetically sealed scroll compressor, a compressor section and a motor section for driving the compressor section are housed and disposed in a hermetically sealed container. The compressor section is constituted by meshing a fixed scroll with a spiral wrap vertically provided on a disk-shaped mirror plate and a orbiting scroll with a spiral wrap vertically provided on a disk-shaped mirror plate with each other with these wraps located on inner sides, engaging the orbiting scroll with an eccentric portion of a crankshaft, causing the orbiting scroll to perform orbiting movement with respect to the fixed scroll without rotating on its axis, and providing the fixed scroll with a discharge port opening to the center portion and an intake port opening to an outer peripheral portion, so as to take in a helium gas from the inlet port, compress the helium gas by moving the compression chambers formed by the fixed scroll and the orbiting scroll to the center to decrease the volume to discharge the helium gas from the discharge port. Further, the compressor section includes an oil injecting mechanism section formed by causing the injection pipe for injecting a fluid to the compression chambers during compression to penetrate through the hermetically sealed container and connect to one oil injecting port which is provided on a wrap tooth groove bottom surface of the fixed scroll. The diameter of the oil injection port is set to be larger than the wrap width of the orbiting scroll.